Flexible fan



, P. NIELSEN Dec. 5, 1939.

FLEXIBLE FAN Filed *A ril '7, 1938 3m entor m Peter Nielsen (Ittomeg Patented Dec. 5, 1939 PATENT OFFICE FLEXIBLE FAN Peter Nielsen, Omaha, Nebr., assignor to Jubilee Manufacturing 00., Omaha, Nebr., a corporation of Nebraska Application April 7, 1938, Serial No. 200,663

1 Claim. (01. 170-159) This invention relates to fans and more particularly air thrust blades and hubs thereof.

A general object of the invention is to provide fans of economical construction comprised 6 of few and simple parts.

Another object of the invention is to provide means for minimizing sounds generated by the blades during an air impelling rotation thereof.

A further object of the invention is to provide means for attaching fan hubs to fan motor shafts without the use of media extraneous to said hubs and shafts.

A primary object of the invention is to provide a flexible connection between the hub and blades of a fan for permitting the blades to have swinging movements in a direction inclined with respect to the axis of the hub at all times.

A still further object of the-invention is to provide a substantially rigid construction of fan blades stamped or cut from sheet metal and die pressed to provide air thrust surfaces thereon which may have wabbling movements with respect to the axis of the blades for permitting the blades to centrifugalize incident to an accidental zedistortion of any of the blades from an initial position.

' Another object of the invention is to provide a construction of fan blades so arranged that the blades are permitted to flex with respect to 30. their supporting hub at times when a foreign object such as a finger of a person contacts with said blades for obviating injury to the blades or said finger.

A further object of the invention is to provide 35 a construction of. fan which may be placed upon I a desk or suspended in an automobile or the like for use without enclosing the blades thereof in- In the drawing Figure 1 is a side elevation ofa fan embodying the present invention as applied to a motor shaft, the housing of the latter 45 and a support for said housing also showing in side elevation.

Figure 2 is a plan view of the new fan. Figure 3 is a transverse section 'of the blades and hub of the fan shown in Figure 2, the view 50 being taken substantially on line 33 of. Figure 2.

'Figure 4 is a longitudinal section of the fan taken on line 4-4 of Figure 3.

As heretofore practiced in the art fans have 68 heenmanufactured of rigid construction between the blades and the hub thereof, necessitating enclosing the blades of the fan in a guard housing, the latter being cumbersome, expensive and not generally of ornate appearance. Also fans have been constructed lately utilizing blades formed of rubber and it is well known that rubber deteriorates rapidly through use and exposure to the air whereby such fans are of short use-life, said rubber fans also being provided with expensively constructed expedients for securing the 10 blades thereof to their hubs, said fans usually not requiring a guard housing and it is a further object of the present invention to obviate said undesirable practices.

Referring now to the drawing for a more par- 15 ticular description it indicates a suction of an automobile body portion, table top, desk or the like environment with which it is desired to associate the fan of the present invention. A ball and socket joint generally indicated at I! may 20 be secured to the surface of .the object 10 by means of screws l2, if desired, said screws or the like being necessarily employed at times when the fan, later described herein, and the driving motor thereof is suspended during certain types of use.

The ball of said joint is provided with a shaft l3 to which a bracket I4 is secured. The bracket encircles and supports a motor housing 15 having a motor, not shown, inside thereof. The motor is connected. to a suitable source of electrical energy and is provided with aswitch for opening and closing a circuit in a well known manner for driving the fan of the present invention.

The shaft of the motor is of a less transverse diameter than the bore ll of a hub l8 at times when said hub I8 is formed of rubber. the latter material preferably being employed for said hub whereby the annular wall of the bore I1 is adapted to contract about the outer end of the shaft I6 at'times when said end is inserted into said bore for securing the hub to the shaft without the employment of set screws, cotter pins or the like lnstrumentalities.

As best shown in Figure 4, the fan further includes a plurality of blades I! which are radially disposed about the hub l8 and as best shown in Figure 3 said blades are spaced away from said hub.

Preferably the blades I! are formed from a 5 greater diameter than the diameter of the hub l8. The said sheet metal is of a gauge or thickness sufficient to provide the blades of a substantially form sustaining character and of substantial rigidity, said blades during the formation thereof each also being preferably provided with apertures 20 for purposes later described. After the blades are cut, either simultaneously or separately, from said sheet of metal they are squeezed in a die to provide air thrust surfaces disposed in a well known manner and as outlined in Figure 1. Preferably during the formation of the blades a plurality of small apertures 2! are provided for centering the blades in a mould.

The mould is provided with upstanding pin detents which extend through the apertures 2! for maintaining the blades in a preselected position within and with respect to the mould, the perimeter of the blades being slightly spaced away from the corresponding shape of the interior walls of the mould, whereby the latter upon receiving a quantity of semi-plastic rubber which is run into the mould causes the rubber to encase or sheath the blades l9 therein, said rubber extending over said perimeters of the blades a distance not greater than one eighth of an inch as best shown in Figure 4 and preferably said rubber also forming the hub I8 at that time, together with an annulus 22 which, as best shown in Figure 3, is preferably of lesser transverse width than the transverse thickness of the rubber casing of the blades for purposes later described.

During the moulding of the rubber sheathing 23 about the blades 19 the rubber flows through the apertures 20 of the blades and congeals to cement both sides of the sheathing 23 of each blade integrally or unitarily together for securing said rubber sheathingto the blades and preventing a loosening of said sheathing at times when the initially live rubber deteriorates or cracks through use and exposure, whereby said sheathing adheres to the blades at all times dur- 7 of rubber as heretofore mentioned, said annulus providing a flexible connection between the blades and the hub.

As thus described it will be noted that the blades I9 when provided with the apertures 20 and encased as above described are provided with air thrust surfaces 24 upon each side thereof which are adapted to impel air toward or away from the motor housing 05 in accordance with the direction of rotation of the shaft of the motor, said blades normally rotating in unison with said shaft in a plane which is at a right angle with respect to the axis of said shaft, the hub, l8

and the annulus 22. The normal rotation of said blades being in a plane bounded by the full lines thereof as shown in Figure l and it will be noted that if a finger or other object, such as the finger outlined at 25, he accidentally or otherwise placed in contact with the blades during a rotation thereof that said blades are thereby caused to move from the full line position thereof to the dotted line position thereof shown in Figure 1 during said rotation and to rotate in a plane bounded by said dotted lines without appreciable injury to said finger and without injury to said blades, said flexible connection permitting the blades to wabble while rotating about their fixed axis for said purpose.

Among other advantages of the present construction it may be mentioned that it often happens during the packing and shipping of merchandise as well as accidents incident to use that one or more of the blades l9 become bent out of their initial position with respect to the other blades of the fan whereby an imbalance is generated during rotation of the blades as heretofore practiced and it will be noted that by means of the'present invention should one of the blades accidentally become misaligned with respect to its mate that the flexible mounting of the rigid fa'nupon the hub thereof will cause said bent fan blades to seek a common plane of rotation with respect to the other blades of the fan and to centrifugalize resultant from centrifugal force generated through rotation of the fan, whereby the eificiency of the fan is not impaired and no additional noise is generated by bent fan blades the latter operating efliciently to impel air.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claim.

I claim:

A fan comprising a plurality of radially arranged metal blade members having an integral central portion, said central portion having an axially disposed opening in said metal, a hub member having 'a; lesser diameter than said opening axially disposed in said opening, said hub being provided with an axially disposed bore for receiving a driver shaft forrotating said hub in a fixed plane, a rubber covering engaging entirely about said blade members and having an annularly disposed portion connected with said hub, said annular portion being relatively thin with respect to the transverse thickness of said covering of the.blades .for permitting said blades to have unitary flexing movements with respect to said hub during a rotation of said hub.

PETER NIELSEN. 

